/Engine/Source/Runtime/Engine/Public/AudioDevice.h
Registers the submix buffer listener with the given submix. A nullptr for SoundSubmix will register the listener with the master submix.
virtual void RegisterSubmixBufferListener ( [ISubmixBufferListener](API\Runtime\Engine\ISubmixBufferListener) * InSubmixBufferListener, [USoundSubmix](API\Runtime\Engine\Sound\USoundSubmix) * SoundSubmix )